Aerospace Engineering Commons^™

Effect Of Perturbations On The Dominant Flow Structures In A Rectangular Lid-Driven Cavity With Particle Suspensions, Siva Bolisetty

Graduate Research Theses & Dissertations

The lid-driven cavity is a canonical problem in the field of analytical and computational fluid dynamics. This work is focused on a 2-D rectangular cavity with a length twice the size of its width and consists of an incompressible fluid with a moving upper wall/lid while the rest of the wall boundaries are subjected to fixed, no-slip, zero-velocity boundary conditions. The objective is to investigate the effect of perturbations resulting from particle drag and particle collisions on dominant flow structures of the fluid within this cavity. The dominant flow structures in a rectangular lid-driven cavity constitute a primary vortex, a …

An Investigation Of The Magneto-Active Slosh Control For Cylindrical Propellant Tanks Using Floating Membranes, Manikandan Vairamani, Pedro Llanos, Balaji Sivasubramanian, Somnath Nagendra, Kevin Crosby

Publications

The phenomenon of sloshing is a substantial challenge in propellant management, particularly in reduced gravity where surface tension-driven flows result in large slosh amplitudes and relatively long decay time scales. Propellant Management Devices (PMDs) such as the rigid baffles and elastomeric membranes are often employed to counteract motion of the free surface. In the present study, we investigate an active PMD that utilizes a free-floating membrane that, under an applied static magnetic field, becomes rigid and suppresses slosh. This semi-rigid structural layer can thereby replace bulky baffle structures and reduce the overall weight of the tank. In this paper, the …

Selective Dielectric Barrier Discharge Actuation For Flow Control Of Delta Wings, Arnab Chatterjee

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Wake Vortex Pair Formation As An Analog For Dust Devil And Tornado Genesis, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

In 1966, meteorologist R.S. Scorer attempted to explain how large-scale oceanic tropical depressions become hurricanes or typhoons. His model was based on the idea that when these large-scale tropical depression structures begin to rotate, mostly due to Coriolis effects, an annular outer portion of that structure changes suddenly to a potential vortex segment, with the same outer radial limit as the low-pressure structure, but with an inner radius that conserves the overall system angular momentum and kinetic energy. By analogy with the "jump" instability describing sudden buckling of a vertical column, this paper shows that his conjecture merits additional consideration. …

Parametric Study Of A Turbofan Engine With An Auxiliary High-Pressure Bypass, Sharanabasaweshwara A. Asundi, Syed Firasat Ali

Mechanical & Aerospace Engineering Faculty Publications

A parametric study of a novel turbofan engine with an auxiliary high-pressure bypass (AHPB) is presented. The underlying motivation for the study was to introduce and explore a configuration of a turbofan engine which could facilitate clean secondary burning of fuel at a higher temperature than conventionally realized. The study was also motivated by the developments in engineering materials for high-temperature applications and the potential utility of these developments. The parametric study is presented in two phases. Phase I presents a schematic of the turbofan engine with AHPB and the mathematics of the performance parameters at various stations. The proposed …

Oscillatory Flow Driven By Cavity, Jeremy Ralph Bonifacio

CGU Theses & Dissertations

Flows past a cavity are known to exhibit an oscillatory behavior with an amplitude and frequency dependent on the incoming flow properties and the geometry of the cavity. Experiments and numerical analyses have been performed to determine the effects of a flow passing through an axisymmetric cavity and discharging into a transverse freestream. The study focuses on the mechanisms involved in the generation of pulsatile flow and its influences on a jet in crossflow. Flow characteristics through the cavity and the jet in crossflow interaction were analyzed using the computational fluid dynamics software Siemens Star-CCM+. The experimental analysis utilized a …

Design And Testing Of A Wind Energy Harnessing System For Forced Convective Drying Of Grain In Low Wind Speed, Warm And Humid Climates, Francis Akumabi Agbali

Theses and Dissertations--Biosystems and Agricultural Engineering

Forced convective drying using a wind turbine mechanically connected to a ventilation fan was hypothesized for low cost and rapid grain drying in developing countries. The idea was tested using an expandable wind turbine blade system with variable pitch, at low wind speeds in a wind tunnel. The design was based on empirical and theoretical models embedded in a graphical user interface (GUI) created to estimate airflow-power requirements for drying ear corn. Output airflow (0.0016 - 0.0052 m³kg^-1s^-1) increased within the study wind speed range (2.0 - 5.5 m/s). System efficiency peak (8.6%) was …

Enhanced Surface Integrity With Thermally Stable Residual Stress Fields And Nanostructures In Cryogenic Processing Of Titanium Alloy Ti-6al-4v, James R. Caudill

Theses and Dissertations--Mechanical and Aerospace Engineering

Burnishing is a chipless finishing process used to improve surface integrity by severe plastic deformation (SPD) of surface asperities. As surface integrity in large measure defines the functional performance and fatigue life of aerospace alloys, burnishing is thus a means of increasing the fatigue life of critical components, such as turbine and compressor blades in gas turbine engines. Therefore, the primary objective of this dissertation is to characterize the burnishing-induced surface integrity of Ti-6Al-4V alloy in terms of the implemented processing parameters. As the impact of cooling mechanisms on surface integrity from SPD processing is largely unexplored, a particular emphasis …

Single-Degree-Of-Freedom Experiments Demonstrating Electromagnetic Formation Flying For Small Satellite Swarms Using Piecewise-Sinusoidal Controls, Ajin Sunny

Theses and Dissertations--Mechanical and Aerospace Engineering

This thesis presents a decentralized electromagnetic formation flying (EMFF) control method using frequency-multiplexed sinusoidal control signals. We demonstrate the EMFF control approach in open-loop and closed-loop control experiments using a single-degree-of-freedom testbed with an electromagnetic actuation system (EAS). The EAS sense the relative position and velocity between satellites and implement a frequency-multiplexed sinusoidal control signal. We use a laser-rangefinder device to capture the relative position and an ARM-based microcontroller to implement the closed-loop control algorithm. We custom-design and build the EAS that implements the formation control in one dimension. The experimental results in this thesis demonstrate the feasibility of the …

Design Process For The Containment And Manipulation Of Liquids In Microgravity, Chris Meek

Theses and Dissertations--Mechanical and Aerospace Engineering

In order to enhance accessibility to microgravity research, the design process for experiments on the ISS must be streamlined and accessible to all scientific disciplines, not just aerospace engineers. Thus, a general design and analysis toolbox with accompanying best practices manual for microgravity liquid containment is proposed. The work presented in this thesis improves the design process by introducing a modular liquid tank design which can be filled, drained, or act as a passive liquid-gas separation device. It can also be pressurized, and used for aerosol spray. This tank can be modified to meet the design requirements of various experimental …

Hybrid Multi-Objective Optimization Of Left Ventricular Assist Device Outflow Graft Anastomosis Orientation To Minimize Stroke Rate, Blake Lozinski

Electronic Theses and Dissertations

A Left Ventricular Assist Device (LVAD) is a mechanical pump that is utilized as a bridge to transplantation for patients with a Heart Failure (HF) condition. More recently, LVADs have been also used as destination therapy and have provided an increase in the quality of life for patients with HF. However, despite improvements in VAD design and anticoagulation treatment, there remains a significant problem with VAD therapy, namely drive line infection and thromboembolic events leading to stroke. This thesis focuses on a surgical maneuver to address the second of these issues, guided by previous steady flow hemodynamic studies that have …

Numerical Simulation Of Non-Premixed And Premixed Axial Stage Combustor At High Pressure, Tyler Worbington

Electronic Theses and Dissertations

Axial-staged combustors represent an important concept that can be applied to reduce NOx emissions throughout a gas turbine engine. There are four main CFD models presented in this study that describe a highly turbulent jet-in-crossflow (JIC) simulation of partially premixed and non-premixed jets with a constant chamber pressure of 5 atm absolute. The equivalence ratio of the partially premixed jet was held constant at rich conditions with a �������� of 4 while the main stage varied from ��1 and ��2 of 0.575 and 0.73 with an average headend temperature of 1415K and 1545K, respectively. Chemistry was reduced by tabulation of …

The Application Of Signal Detection Theory Principles To Aircraft Certification, John M. Maris Ph.D, Alexander V. Ilyin Ph.D

International Journal of Aviation, Aeronautics, and Aerospace

This paper presents the application of Signal Detection Theory (SDT) concepts to the certification of optional systems that provide operational or system safety benefits. The method and analysis yield quantitative requirements for the system performance that account for the risks and benefits of the potential system. This is in contrast to the standard certification approach which only focuses on Failure Conditions, and does not examine potential system benefits. A case study of an aircraft spotter on an electronic moving map illustrates that substantial safety improvements may be achieved even with the relatively low levels of software reliability associated with Commercial …

Fe Modeling Methodology For Load Analysis And Preliminary Sizing Of Aircraft Wing Structure, Jun Hwan Jang, Sang Ho Ahn

International Journal of Aviation, Aeronautics, and Aerospace

It is a critical part at the basic design phase of aircraft structural design to build a finite element model and it will have a direct impact on time and cost for airframe structure development. In addition, the objective of finite element model will be varied depending on each design review phase and the modelling methodology varied accordingly. In order to build an effective and economic finite element model, it is required to develop adequate level of modelling methodology based on each design phase and its objectives. Therefore, in this paper, the finite element modeling methodology was presented for internal …

Comparison Of Fixed-Wing Unmanned Aircraft Systems (Uas) For Agriculture Monitoring, Joseph Cerreta, Kristine M. Kiernan

International Journal of Aviation, Aeronautics, and Aerospace

Florida citrus growers need inexpensive methods to observe citrus plants to detect disease and stress consistently. Health vegetation indices, such as the Normalized Difference Vegetation Index (NDVI) collected from Unmanned Aircraft Systems (UAS), can be used to identify variation in plant health. Simple-to-operate UAS may enable growers to determine within-field variation more frequently than with inspections from scouts, providing more frequent knowledge about the crop condition. This research compared two low-cost fixed-wing UAS, a $5,000 Parrot Disco Pro Ag and a $16,690 senseFly eBee, each equipped with a Parrot Sequoia multispectral camera, to determine if there were differences in the …

In-Flight Wingtip Folding: Inspiration From The Xb-70 Valkyrie, Gaétan X. Dussart, Mudassir Lone, Ciaran O'Rourke, Thomas Wilson

International Journal of Aviation, Aeronautics, and Aerospace

Wingip folding can be used to extend aircraft wingspan, allowing designers to take advantage of reduced induced drag whilst respecting ground operational limitations. Such devices can also be used in-flight for a variety of other benefits including load alleviation and flight control. The majority of in-flight folding research takes inspiration in past developments made on the XB-70 Valkyrie, which used the folding devices for stability and lift performance benefits. In this paper, the authors investigate the capabilities of the folding wingtip system and potential scaling to large civil aircraft. Manufacturing details are used to size the actuators whilst the aerodynamic …

Effects Of A Hand Luggage Guiding System On Airplane Boarding Time And Passenger Experience, Mirte Vendel, Sagar Dangal, Jessica Coppens, Suzanne Hiemstra-Van Mastrigt, Peter Vink

International Journal of Aviation, Aeronautics, and Aerospace

This research investigates whether a hand luggage guiding system in overhead bins decreases boarding time and improves boarding experience during aircraft boarding process. A guiding system was developed which allocates and displays the passengers luggage space in the overhead bin. The allocated space is guided by a light strip in front of the display that blinks when a passenger comes close to their allocated luggage space. This system was tested in a Boeing 737 test fuselage. Compared to regular boarding, a boarding time reduction of 16 to 23 seconds was estimated using the hand luggage guiding system in groups of …

Global Aviation System: Towards Sustainable Development, Marina P. Bonser Dr.

International Journal of Aviation, Aeronautics, and Aerospace

Aviation around the world has integrated into a global system. As the integration process continues, more aspects and levels of it need to be lead towards the sustainable development of the whole system via advancing strategic management, global communication proficiency, and technological expertise. It becomes essential to enrich global language (English) proficiency with cross-cultural communication competence not only for communication in the air but also for airport security, passenger and cargo services, aircraft and equipage engineering, building, and maintenance. Nowadays lower levels of management need more advanced strategic thinking and problem solving skills, and higher levels of management need global …

Determination Of Parameters During Quasi-Steady Stall Maneuver Using Genetic Algorithm, Ambuj Srivastava, Ajit Kumar, Ajoy Kanti Ghosh

International Journal of Aviation, Aeronautics, and Aerospace

The current work offers the determination of longitudinal aerodynamic derivatives during flight manoeuver at angles of attack near the stall. The flight manoeuver near stall is highly non-linear in nature due to separated flow at such elevated angles of attack. Kirchoff’s model for Quasi-Steady Stall Modelling (QSSM) is employed to represent the non-linear nature of aerodynamics during flight manoeuver at elevated angles of attack close to the stall. The Genetic Algorithm (GA) optimized output error method is utilized for estimating the parameters specific to stall characteristics and longitudinal aerodynamics of the ATTAS aircraft. The comparative evaluation of the parameter estimates …

Determination Of Aerodynamic Forces And Control Requirement During Ground Effect, Ambuj Srivastava

International Journal of Aviation, Aeronautics, and Aerospace

The current work delivers the effect of ground proximity on longitudinal aerodynamic forces and the elevator deflection required for trimming the aircraft. The academic understanding states that the with the increasing proximity to the ground,downwash progressively reduces.The methodology adopts the approximation of linear decrement for the estimation of the residual downwash at any height above ground within the unit wingspan. The proposed method utilizes non-dimensional height above ground for the approximation of effective downwash angle in the presence of ground. The approximately predicted effective downwash angle is subsequently utilized to estimate the effect of ground proximity on longitudinal forces, trim …

A Thrust Equation Treats Propellers And Rotors As Aerodynamic Cycles And Calculates Their Thrust Without Resorting To The Blade Element Method, Phillip -. Burgers

International Journal of Aviation, Aeronautics, and Aerospace

The lift generated by a translating wing of known translational speed, lift coefficient and area is calculated by a simple equation. A propeller or rotor generating thrust share the same aerodynamic principles but their different kinematics cause the calculation of their thrust to be laborious. This paper derives a thrust equation from an algebraic expansion of the Prandtl’s dynamic pressure term q_∞by adding the rotational kinetic energy of a propeller or rotor to the existing translational kinetic energy term. This thrust equation can be applied directly to propellers and rotors and assumes these to operate as cycles with …

Optimization And Analysis Of An Elite Electric Propulsion System, Mehakveer Singh, Kapil Yadav, Satnam Singh, Vikas Chumber, Harikrishna Chavhan

International Journal of Aviation, Aeronautics, and Aerospace

Abstract- Electric propulsion has a promising system to create new possibilities in this technological era as well as control the harmful gaseous emission. This paper put a vision on several parameters of electric propulsion. The engine’s performance is comparable to the current propulsion devices and provides a lightweight solution to the robust technologies’ dependent on chemical energy sources. There are a plethora of factors which is enhanced by electric propulsion such as, overall efficiency, capabilities, and robustness of future air vehicles as well as mainly overcome from exhaust hazards. Electric propulsion systems have the potential of utilizing the electrically-driven propulsion …

Effect Of Chemical Reactions On The Fluidic Thrust Vectoring Of An Axisymmetric Nozzle, Rachid Chouicha, Mohamed Sellam, Said Bergheul

International Journal of Aviation, Aeronautics, and Aerospace

Abstract:

During the last years, several thrust control systems of aerospace rocket engines have been developed. The fluidic thrust vectoring is one of them; it is simple in design and offers a substantial gain in weight and in performance. Most of studies related to this device were carried out with cold gas. It’s quite legitimate to expect that the thermophysical properties of the gases may affect considerably the flow behavior. Besides, the effects of reacting gases at high temperatures, under their effects all flow parameters like to vary.

This study aims to develop a new methodology that allows studying and …

Computation Of Eclipse Time For Low-Earth Orbiting Small Satellites, Sumanth R M

International Journal of Aviation, Aeronautics, and Aerospace

This paper addresses a method for computing eclipse and daylight time for satellites in LEO. Continuous health-monitoring of the satellite is required for the success the mission. For this, the satellites are primarily powered by solar energy but during the eclipse time, the satellite’s functioning is affected as it cannot generate power during this period and also, its temperature drops rapidly. To tackle these issues, computing eclipse time for satellites becomes essential so as to plan for sizing its secondary power source for continuous functioning. In this work, eclipse time is being computed and it is shown that eclipse time …

Comparison Of Flow Field In The Proximity Of A Single Planar & Wrap-Around Fin, Nayhel Sharma, Palak Saini, Hrishabh Chaudhary, Gurteg Nagi, Rakesh Kumar Dr.

International Journal of Aviation, Aeronautics, and Aerospace

Abstract

This paper analyses the results of the computational analysis between a single planar and a wrap-around fin mounted on a semi-cylindrical body. A free-stream Computational Fluid Dynamics (CFD) model was simulated for both cases in the Mach 0.4-3.0M range at 0°Angle of attack, in which, the behavior of flow around the fin was investigated using a turbulence model of higher order discretization. The post-processing shows all the possible views of the flow dynamics around the fins, as well as the missile body. The aerodynamic drag and the rolling moment characteristics of the planar and the wrap-around fin have been …

Design And Realization Of An Unmanned Aerial Rotorcraft Vehicle Using Pressurized Inflatable Structure, Nirmal Sadasivan

International Journal of Aviation, Aeronautics, and Aerospace

Unmanned aerial rotorcraft vehicles have many military, commercial and civil applications. There is a necessity to advance the performance on several ranges of rotorcraft for using these vehicles successfully in the expanded future roles. A lower flight time, noise disturbance and safety issues remain the key obstacles in increasing the efficiency of the rotorcraft for various applications. This work presents the design and realization of a rotorcraft using pressurized inflatable structure filled with lighter than air gas such as helium or hydrogen to provide lift assistance for the vehicle. Two iterative design procedures were developed for designing the vehicle. One …

A Comparative Aerodynamic Study Of Nonplanar Wings, Mondher Yahyaoui

International Journal of Aviation, Aeronautics, and Aerospace

In this work four nonplanar wing configurations were studied using the vortex-lattice method: the wing-winglet, the C-wing, the biplane, and the box wing. It has been shown that linear twist, which is more practical in aeronautical construction, is more than adequate to achieve the higher values of span efficiency factor obtained by a completely optimized twist distribution along the span camber, the latter being in general highly varying and thus not very practical. It has also been shown that moderate sweep can slightly increase the span efficiency factor and further reduce vortex drag. The increase is more important for the …

Double Stud Cargo Fitting Research, Alternative Cargo Clip Design And Analysis, Cemal İrfan Çalişkan, Ebubekir Koç Dr, Hamaid Mahmood Khan Dr, Mustafa Enes Bulduk

International Journal of Aviation, Aeronautics, and Aerospace

It can be said that today's civil aviation basics began to be laid in the 1950s. This date is also important as the period in which the rules are being written and at the same time, some system solutions are produced by testing the methods of cargo loading. The cargo clip used in these cargo loading systems will be the subject of our article. In this context, the development process of the clip, which started in 1953 until today, will be examined in the light of the patent applications of the period; Afterwards, alternative clip-on work to the current cargo …

Design Guidelines For Supersonic Aircrafts In Civil Aviation, Tridib Banerjee Mr.

International Journal of Aviation, Aeronautics, and Aerospace

There exists no publication currently available to the scholars that address in detail, every aspect of designing a modern supersonic aircraft for civil aviation. This paper aims to resolve that issue. It reviews all the existing work that has been done on the topic so far and builds upon that. It incorporates multiple disciplines and takes into account the closely inter-coupled effects of each component on one-another. It also analyses in detail the various environmental and modern regulatory challenges like sonic boom and means to overcome them. It further addresses the challenges like logistics, cabin crew radiation exposure, and cost …

Simulations On Optimization Of Liquid Spray Burners & Operating Parameters, Pallavi Gajjar, Vinayak Malhotra

International Journal of Aviation, Aeronautics, and Aerospace

Spray burners form an essential part of any liquid propulsion system as they are responsible for injecting, atomizing, mixing and combusting the liquid fuel. Spray combustion used in aerospace applications like the liquid rocket engines, gas turbines or any other controlled environment for that matter places a huge emphasis on safe and effective operations. These applications make use of relatively small amounts of propellant volumes to generate enormous amounts of energy through combustion for producing thrust. For such cases involving enormous energy interactions, combustion comes with its own set of challenges. The predominant challenge among them all is that of …